Solve with first order logic (predicates logic) In the elf island: - Elves can be: evil, good or normal. (Is not an exclusive or) Good elves have magic powers and don't have three eyes. - Evil elves have three eyes and don't have magic powers. Wants to demonstrate this conclusion: If any inhabitant has magic powers and has three eyes then it is normal. Modeling: Model a problem (hypothesis and conclusion) with predicates and quantifiers. Use the following predicates: B(h): h is good M(h): h is evil R(h): h is normal P(h): h has magic powers - T(h): h has three eyes Deduction: Demonstrates the validity of the conclusion